Front contacted electrical component

ABSTRACT

A pile or layer condensor is provided with external connecting wires on its two frontal sides by pressing the connecting wires into an outer metallic layer which has a lower melting point than an inner metallic layer which contacts the plates of the condensor. The connecting wires are thereby embraced by the outer layer and adhere to the inner layer.

United States Fatent Behn et al.

[451 Sept. 26, 1972 FRONT CONTACTED ELECTRICAL COMPONENT Inventors:Reinhard Behn, Munich; Heinrich Gottlob, Regensburg; Gerhard Hoyler,Munich; l-lartmut Kessler, Regensburg, all of Germany Assignee: SiemensAktiengesellschaft, Berlin and Munich, Germany Filed: Sept. 22, 1970Appl. No.: 74,473

Related US. Application Data Division of Ser. No. 841,860, July 15,1962, abandoned.

us. Cl. ..29/492, 29/502, 29/570, 29/590, 29/628 rm. Cl. ..B23k 31/02Field of Search ..29/492, 502, 628, 590, 570, 29/587 BFiQOSmm B iOo5mmllil l L R 1'0 ZSmmMI) [56] References Cited UNITED STATES PATENTS2,418,461 4/ 1947 Becker et a1 ..29/492 X 2,953,673 9/1960 Bouton et al..29/628 UX 3,304,475 2/ 1967 Gowen et a1 ..317/216 3,384,958 5/ 1968Christian et a1 ..29/502 X 3,504,244 3/ 1970 Chiba et al ..29/492 X3,512,051 5/1970 N011 ..29/502 UX Primary Examiner-John F. CampbellAssistant Examiner-Ronald J. Shore Att0rney--Hill, Sherman, Meroni,Gross & Simpson [5 7] ABSTRACT A pile or layer condensor is providedwith external connecting wires on its two frontal sides by pressing theconnecting wires into an outer metallic layer which has a lower meltingpoint than an inner metallic layer which contacts the plates of thecondensor. The connecting wires are thereby embraced by the outer layerand adhere to the inner layer.

4 Claims, 1 Drawing Figure o, iolmmml l This application is a divisionof Ser. No. 841,860,

filed July 15, 1962, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to electrical components, and more particularly to the provisionof connecting wires to such components.

2. Description of the Prior Art Pile or layer condensors which areproduced from a master condensor wound on a drum by dividing the mastercondensor in the radial direction and in the circumferential directionhave what are termed frontal sides, which sides have a metallic layerapplied thereto for commonly connecting the condensor plates of likeplurality. Each condensor usually has two such frontal sides. Layercondensors and other electrical elements, such as resistances, arefrequently installed into printed conductor plates in a verticalassembly. Holes are placed into the conductor plate with a standardizedscreen dimension and it is into these holes that the connecting wiresare inserted and soldered during assembly of the particular circuit. Thedistance of the connecting wires at the building component may vary onlyin very definite limits due to the predetermined tolerance of thedistance and diameters of holes. In order to maintain this screendimension substantially constant, it is heretofore been a practice toprovide space holders at the building element, for example, bottomplatelets or cups with perforations. Alternatively, the distance isdetermined with the aid of a device when the wires are applied, forexample with the aid of a gauge when the wires are soldered on.Moreover, in the known methods the distance can be adjusted during apressing operation, or the distance is produced mechanically only priorto insertion into the conductor plate. These methods are complicated anddifficult to perform, and in some cases entail considerable cost.

It is therefore highly desirable and a primary object of the presentinvention to provide techniques for maintaining the distance of theconnecting wires of electrical components such as condensors andresistors initially within a certain tolerance.

SUMMARY OF THE INVENTION According to the invention the distance of theexternal connecting wires of an electrical component is determined byapplying a first contact layer to the component having a higher meltingpoint than a second contact layer which is applied over the firstcontact layer. The contact wires are then pressed into the metal of thesecond contact layer whereupon they are embraced thereby and adhere tothe first contact layer. Heat is applied to assist in forcing theconnecting wires through the second or outer contact layer.

The foregoing shows a possibility of assuring the maintenance of thescreen tolerance by the design of the electrical element itself. Forexample, a so-called layer, pile or stack condensor is actuallyfabricated in such a manner that partial pieces with the desiredcapacity are cutout of an annularly coiled body which is wound on a drumand contacted by means of metal spraying techniques which are known inart per se, two such metal layers being provided, one for each set ofcapacitor plates of like polarity. For resistors, two superposed metallayers would be provided where required for each terminal of theresistor.

BRIEF DESCRIPTION OF THE DRAWING Other objects, features and advantagesof the invention will be readily apparent from the following detaileddescription of a preferred embodiment thereof, taken in conjunction withthe accompanying drawing, although variations and modifications may beeffected without departing from the spirit and scope of the novelconcepts of the disclosure, and in which the single figure illustrates astack or layer condensor having connecting wires provided according tothe invention, the condensor being shown in cross-section.

DESCRIPTION OF THE PREFERRED EMBODIMENT As stated above, the presentinvention may be employed for a variety of electrical components.Inasmuch as the invention may be advantageously employed for layer typecondensors, the description herein is directed to such condensors andthe application of the invention to other components will be readilyunderstood by those skilled in the art.

In contacting the electrical components, here a layer condensor,according to the invention, the preferred method comprises the provisionof two superposed layers of metal for contacting the connecting wire.The outermost layer of metal is softened by heating and the connectingwire is pressed into the softened metal until it strikes and adheres tothe inner metal layer. The inner metal layer has a higher melting pointthan the outer metal layer and melting of the inner layer is preventedby applying only sufficient heat and pressure to permit pressing of theconnecting wire through the outer layer.

The inner layer which is employed for contacting the thin metalcondensor plates and which has a high melting point is providedpreferably as aluminum and/or copper and the outer contact layeremployed for the application of the connecting wires is providedpreferably from SnPb, white metal or babbitt metal 10. The contacting ofthe connecting wires within the outer layer is best accomplished bybonding. By an appropriate dosification of the bonding energy, theconnecting wires can be applied under radial connection such that theycompletely penetrate the low melting point outer metal layer and adhereto the high melting point inner metal layer, which must not be changedby the bonding energy, the surface of the inner layer which is adjacentand contacting the outer layer only adhering to the connecting wire. Inthis manner, the wire distance is determined. The total tolerance of thedistance of both connecting wires results from the coiling precision ofthe master coil and from the thickness tolerance of the first contactlayer which has the high melting point.

Referring to the drawing, a stack or layer capacitor is provided withconnecting wires according to the present invention and includesmetallic layers 2 carried by dielectricum foils l in a superposedconstruction. Alternate layers overlap on opposite sides of thecondensor, the frontal sides, to which is applied a first metallic layer3 having a high melting point, for example, aluminum and/or copper.

Second frontal metallic contact layers 4 are applied over the layers 3from a metal having a lower melting point, for example. SnPb, whitemetal or babbitt metal 10. The frontal layers 4 are softened by heatingand the connecting wires 5 are pressed into the layers 4 and therebybonded thereto. The connecting wires 5 are pressed into layer 4 untilthey contact the inner layer 3, which through controlled application ofheat is not softened due to its higher melting point. Thus, the overallwire diameter A and/or the screen dimension R can be maintained simplyin all layer capacitors in a rather exact reproducability.

In a layer condensor as illustrated herein, the layers have a width Bwith a tolerance of 0.05mm. The foil width has no influence whendetermining the total tolerance A I but the winding width B does hassuch an influence. The latter is wider in view of the staggeredarrangement of opposite pularity metallic layers 2 carried by thedielectricum layers 1. The tolerance occuring at the winding width B is1 0.05 mm. Furthermore, the tolerance of the thickness of the firstcontact layer 3 is A1 0.1 mm which is also included in determining thetotal tolerance Al. Consequently, for the overall wire distance A and/orfor the screen dimension R of both the connecting wires the totaltolerance may be stated by the expression AI Al 2 A1 With the aid ofappropriate means, the conditions of wire feed, quantity of gas passingthrough andthe size of the spray cone for applying the layers can bemaintained constant and thus the imprecision of the layer thickness A1can easily be maintained within i 0.1 mm, so that for the wire distanceAl= 0.25 mm results as the overall thickness.

Generally then there has been described techniques for securingconnecting wires to electrical components whereby a highly precisearrangement of the connecting wires in accordance with the distancebetween the wires is achieved for aiding the application of suchcomponents as building blocks of electrical circuit assemblies.

What we claim is:

1. In a method of producing a frontally contacted electric layercapacitor from a parent capacitor of the type which has been wound on adrum, an improvement in attaching contact wires to the respectivefrontal surfaces and spaced at a predetermined distance, in particularthe distance between holes in a printed circuit, comprising the stepsof: spraying on each frontal surface a first layer of metal having afirst melting point and simultaneously providing a thickness of thesprayed first layers so as to have external surfaces spaced equal to thepredetermined distance; spraying on each first layer a second layer ofmetal having a second melting point lower than the first melting point;and heating to soften the second layers and pressing respective contactwires through the respective softened second layers to band the contactwires to the respective first layers without changing the first metallayers.

2. In an improvement as set forth in claim 1, comprising the step ofheating the second layers during the step of gressing'without meltingthe first layers,

. In an improvement as set forth in claim 2, wherein the step ofspraying first layers is further defined as spraying first layers ofmetal selected from the group consisting of copper, aluminum and alloysof copper and aluminum.

4. In an improvement as set forth in claim 3, wherein the step ofspraying second layers is further defined as spraying second layers ofmetal selected from the group consisting of SnPb, white metal andbabbitt metal 10.

2. In an improvement as set forth in claim 1, comprising the step ofheating the second layers during the step of pressing without meltingthe first layers.
 3. In an improvement as set forth in claim 2, whereinthe step of spraying first layers is further defined as spraying firstlayers of metal selected from the group consisting of copper, aluminumand alloys of copper and aluminum.
 4. In an improvement as set forth inclaim 3, wherein the step of spraying second layers is further definedas spraying second layers of metal selected from the group consisting ofSnPb, white metal and babbitt metal 10.